Conventional tarp covering systems for trucks include a pair of pivoting arms on opposed sides of an open top container that rotate between a retracted, stowed position in front of the container to an extended unfurled position at the rear wherein the tarp or flexible cover covers the container. The arms project laterally from the sides of the container and increase the overall width of the vehicle. The actuators are generally hydraulic cylinders located outboard of the container and pivot the arms about a fixed shafts. Because of the operating environment for such vehicles, the outboard locations of such components are prone to impact damage. Moreover, in certain jurisdictions, regulations limit vehicle width and accordingly it would be desirable to provide a tarp covering system affording the benefits of current system while complying with applicable restrictions. Examples of such systems include U.S. Pat. No. 5,031,955 to Searfoss, U.S. Pat. No. 4,874,196 to Goldstein, U.S. Pat. No. 4,516,802 to Compton, U.S. Pat. No. 5,058,956 to Godwin, and U.S. Pat. No. 5,129,698 to Cohrs. These systems employ pivoting arms mounted on laterally fixed pivots and accordingly are substantially wider than the container.
Partially laterally retractable pivoting arms have been proposed as disclosed in European Patent 0 581 512 A1. The pivoting arms are laterally retracted by hydraulic cylinders in the forward and rearward positions. While presenting a narrower width than the fixed pivot arms, the arms remain laterally exterior of the container adding to the overall transit width of the vehicle, and if subject to width regulation reduce the width of allowable containers.
It is an object of the present invention to provide a load covering system for open top containers wherein the pivoting arms for deploying the flexible cover reside laterally interior of the sides of the container during travel. A further object is to provide a load covering system wherein the actuators for the arms are located laterally within the sidewalls of the container.
The foregoing object is accomplished in the present invention by pivoting arms mounted on cantilevered rotating shafts that may be laterally retracted and parked beneath the container in both the extended and retracted positions so as not to increase vehicle width during travel and to protect the actuators from damage during transit and operation. According to the invention, a tarp assembly for covering an open top container of a truck, comprises a pair of articulating arm assemblies including lower arms pivotally connected at outer ends to the inner ends of upper arms, said lower arms pivotally connected at lower ends on opposed lateral sides of the container and rotationally mounted adjacent the base of the container about midway along the length of the container; a lateral actuator means for shifting the arm assemblies between a normal retracted position inwardly of the sides of the container and an extended position outwardly of the sides of the container, the lower arms located beneath said container in said retracted position, the upper arms located adjacent an end wall of the container in said retracted position; a retractable flexible cover transversely carried at one end to the outer ends of the arm assembly and connected adjacent the front end of the container at the other end; a rotary actuator for rotating the arm assemblies in said extended positions between forward position wherein said cover is stowed forward of the container and a rearward position wherein said cover overlies the container; and linear actuators connected between said upper arms and said lower arms for varying the angularity therebetween during movement between the forward position and the rearward position.
In another embodiment, particularly suited for container and truck configurations where there are limited mounting locations at the longitudinal center of the chassis, the pivoting arm assemblies are mounted on laterally telescoping rotary actuators, the arm assemblies including telescoping including upper and lower arm sections coupled with linear hydraulic cylinders for extension or retraction, the arrangement allowing the arm assemblies to rotate 180° in the laterally extended position whereby the container cover may be deployed over the open container top, and parked beneath and inward of the container. The arm assemblies are directly rotated from the cantilevered shafts on rotary actuators mounted on the chassis, inwardly of the normal location of prior art actuating systems and within the lateral confines of and beneath the container.